Poor dear! Sounds like some separation anxiety, maybe?
DS just started this about a couple of weeks ago. He's never really let me do the PU/PD thing. He either thinks it's time to play, or it just stimulates him. So, that's out. And if I look him in the eyes, that also stimulates him. (And that's what I think the book means, that you should be out of your LOs eye sight because if you were to look in most babies' eyes, it would stimulate them.) Also, if I stood over him in his crib to try and comfort him, he would roll all over the crib - basically thinking I'm there to play, even if I'm not looking at him or talking to him at all.
So, here's what I've been doing instead. I do the whole bedtime ritual, and, instead of standing over the crib until he drops off, I sit on the floor next to his crib. That way, he can still see me, but I'm looking away from him, not down at him. Also, I'm at eye level so he can watch me while he's laying down. Another plus! (Meaning, he doesn't have to sit up or lift his head to see me across the room.) I might sing softly to him or whisper comforting things to him if I think he might need it. Most times I'm completely quiet. The longest I've had to sit on the floor next to his crib (so far) is 15 minutes. (But I think the phone ringing in the middle of him trying to drop off was the main problem here! :roll: ) Usually he just stares at me and drops off, or turns his head and drops off.
HTH!
Hugs!